A vehicle control unit may be configured to execute an engine brake torque control in which engine torque is controlled to restrict a wheel or wheels from locking when the wheels tend or are about to lock as a result of engine brake (for example, refer to JP-2003-293818-A). In such technique, a torque increase (a torque increment) of the engine torque may be set based on slip amounts of the wheels.
Such technique requires an accurate slip amount to appropriately set the torque increment. The slip amount is calculated based on a body speed (vehicle body speed) and wheel speeds, and the wheel speeds are normally accurately obtained from wheel speed sensors.
Thus, an accurate estimation of the body speed is important to acquire an accurate slip amount. On the other hand, the body speed may not always be accurately estimated depending on road surface conditions. As a result, the torque increment may also not be appropriately set.